1 /* ------------------------------------------------------------------------- */ 2 /* */ 3 /* i2c.h - definitions for the i2c-bus interface */ 4 /* */ 5 /* ------------------------------------------------------------------------- */ 6 /* Copyright (C) 1995-2000 Simon G. Vogl 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 21 MA 02110-1301 USA. */ 22 /* ------------------------------------------------------------------------- */ 23 24 /* With some changes from Kyösti Mälkki <[email protected]> and 25 Frodo Looijaard <[email protected]> */ 26 #ifndef _LINUX_I2C_H 27 #define _LINUX_I2C_H 28 29 #include <linux/mod_devicetable.h> 30 #include <linux/device.h> /* for struct device */ 31 #include <linux/sched.h> /* for completion */ 32 #include <linux/mutex.h> 33 #include <linux/rtmutex.h> 34 #include <linux/irqdomain.h> /* for Host Notify IRQ */ 35 #include <linux/of.h> /* for struct device_node */ 36 #include <linux/swab.h> /* for swab16 */ 37 #include <uapi/linux/i2c.h> 38 39 extern struct bus_type i2c_bus_type; 40 extern struct device_type i2c_adapter_type; 41 extern struct device_type i2c_client_type; 42 43 /* --- General options ------------------------------------------------ */ 44 45 struct i2c_msg; 46 struct i2c_algorithm; 47 struct i2c_adapter; 48 struct i2c_client; 49 struct i2c_driver; 50 struct i2c_device_identity; 51 union i2c_smbus_data; 52 struct i2c_board_info; 53 enum i2c_slave_event; 54 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 55 56 struct module; 57 struct property_entry; 58 59 #if IS_ENABLED(CONFIG_I2C) 60 /* 61 * The master routines are the ones normally used to transmit data to devices 62 * on a bus (or read from them). Apart from two basic transfer functions to 63 * transmit one message at a time, a more complex version can be used to 64 * transmit an arbitrary number of messages without interruption. 65 * @count must be be less than 64k since msg.len is u16. 66 */ 67 extern int i2c_transfer_buffer_flags(const struct i2c_client *client, 68 char *buf, int count, u16 flags); 69 70 /** 71 * i2c_master_recv - issue a single I2C message in master receive mode 72 * @client: Handle to slave device 73 * @buf: Where to store data read from slave 74 * @count: How many bytes to read, must be less than 64k since msg.len is u16 75 * 76 * Returns negative errno, or else the number of bytes read. 77 */ 78 static inline int i2c_master_recv(const struct i2c_client *client, 79 char *buf, int count) 80 { 81 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 82 }; 83 84 /** 85 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 86 * using a DMA safe buffer 87 * @client: Handle to slave device 88 * @buf: Where to store data read from slave, must be safe to use with DMA 89 * @count: How many bytes to read, must be less than 64k since msg.len is u16 90 * 91 * Returns negative errno, or else the number of bytes read. 92 */ 93 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 94 char *buf, int count) 95 { 96 return i2c_transfer_buffer_flags(client, buf, count, 97 I2C_M_RD | I2C_M_DMA_SAFE); 98 }; 99 100 /** 101 * i2c_master_send - issue a single I2C message in master transmit mode 102 * @client: Handle to slave device 103 * @buf: Data that will be written to the slave 104 * @count: How many bytes to write, must be less than 64k since msg.len is u16 105 * 106 * Returns negative errno, or else the number of bytes written. 107 */ 108 static inline int i2c_master_send(const struct i2c_client *client, 109 const char *buf, int count) 110 { 111 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 112 }; 113 114 /** 115 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 116 * using a DMA safe buffer 117 * @client: Handle to slave device 118 * @buf: Data that will be written to the slave, must be safe to use with DMA 119 * @count: How many bytes to write, must be less than 64k since msg.len is u16 120 * 121 * Returns negative errno, or else the number of bytes written. 122 */ 123 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 124 const char *buf, int count) 125 { 126 return i2c_transfer_buffer_flags(client, (char *)buf, count, 127 I2C_M_DMA_SAFE); 128 }; 129 130 /* Transfer num messages. 131 */ 132 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 133 int num); 134 /* Unlocked flavor */ 135 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 136 int num); 137 138 /* This is the very generalized SMBus access routine. You probably do not 139 want to use this, though; one of the functions below may be much easier, 140 and probably just as fast. 141 Note that we use i2c_adapter here, because you do not need a specific 142 smbus adapter to call this function. */ 143 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 144 unsigned short flags, char read_write, u8 command, 145 int protocol, union i2c_smbus_data *data); 146 147 /* Unlocked flavor */ 148 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 149 unsigned short flags, char read_write, u8 command, 150 int protocol, union i2c_smbus_data *data); 151 152 /* Now follow the 'nice' access routines. These also document the calling 153 conventions of i2c_smbus_xfer. */ 154 155 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 156 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 157 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 158 u8 command); 159 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 160 u8 command, u8 value); 161 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 162 u8 command); 163 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 164 u8 command, u16 value); 165 166 static inline s32 167 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 168 { 169 s32 value = i2c_smbus_read_word_data(client, command); 170 171 return (value < 0) ? value : swab16(value); 172 } 173 174 static inline s32 175 i2c_smbus_write_word_swapped(const struct i2c_client *client, 176 u8 command, u16 value) 177 { 178 return i2c_smbus_write_word_data(client, command, swab16(value)); 179 } 180 181 /* Returns the number of read bytes */ 182 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 183 u8 command, u8 *values); 184 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 185 u8 command, u8 length, const u8 *values); 186 /* Returns the number of read bytes */ 187 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 188 u8 command, u8 length, u8 *values); 189 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 190 u8 command, u8 length, 191 const u8 *values); 192 extern s32 193 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 194 u8 command, u8 length, u8 *values); 195 int i2c_get_device_id(const struct i2c_client *client, 196 struct i2c_device_identity *id); 197 #endif /* I2C */ 198 199 /** 200 * struct i2c_device_identity - i2c client device identification 201 * @manufacturer_id: 0 - 4095, database maintained by NXP 202 * @part_id: 0 - 511, according to manufacturer 203 * @die_revision: 0 - 7, according to manufacturer 204 */ 205 struct i2c_device_identity { 206 u16 manufacturer_id; 207 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 208 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 209 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 210 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 211 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 212 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 213 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 214 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 215 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 216 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 217 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 218 #define I2C_DEVICE_ID_FLIR 11 219 #define I2C_DEVICE_ID_O2MICRO 12 220 #define I2C_DEVICE_ID_ATMEL 13 221 #define I2C_DEVICE_ID_NONE 0xffff 222 u16 part_id; 223 u8 die_revision; 224 }; 225 226 enum i2c_alert_protocol { 227 I2C_PROTOCOL_SMBUS_ALERT, 228 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 229 }; 230 231 /** 232 * struct i2c_driver - represent an I2C device driver 233 * @class: What kind of i2c device we instantiate (for detect) 234 * @attach_adapter: Callback for bus addition (deprecated) 235 * @probe: Callback for device binding - soon to be deprecated 236 * @probe_new: New callback for device binding 237 * @remove: Callback for device unbinding 238 * @shutdown: Callback for device shutdown 239 * @alert: Alert callback, for example for the SMBus alert protocol 240 * @command: Callback for bus-wide signaling (optional) 241 * @driver: Device driver model driver 242 * @id_table: List of I2C devices supported by this driver 243 * @detect: Callback for device detection 244 * @address_list: The I2C addresses to probe (for detect) 245 * @clients: List of detected clients we created (for i2c-core use only) 246 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 247 * 248 * The driver.owner field should be set to the module owner of this driver. 249 * The driver.name field should be set to the name of this driver. 250 * 251 * For automatic device detection, both @detect and @address_list must 252 * be defined. @class should also be set, otherwise only devices forced 253 * with module parameters will be created. The detect function must 254 * fill at least the name field of the i2c_board_info structure it is 255 * handed upon successful detection, and possibly also the flags field. 256 * 257 * If @detect is missing, the driver will still work fine for enumerated 258 * devices. Detected devices simply won't be supported. This is expected 259 * for the many I2C/SMBus devices which can't be detected reliably, and 260 * the ones which can always be enumerated in practice. 261 * 262 * The i2c_client structure which is handed to the @detect callback is 263 * not a real i2c_client. It is initialized just enough so that you can 264 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 265 * else with it. In particular, calling dev_dbg and friends on it is 266 * not allowed. 267 */ 268 struct i2c_driver { 269 unsigned int class; 270 271 /* Notifies the driver that a new bus has appeared. You should avoid 272 * using this, it will be removed in a near future. 273 */ 274 int (*attach_adapter)(struct i2c_adapter *) __deprecated; 275 276 /* Standard driver model interfaces */ 277 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 278 int (*remove)(struct i2c_client *); 279 280 /* New driver model interface to aid the seamless removal of the 281 * current probe()'s, more commonly unused than used second parameter. 282 */ 283 int (*probe_new)(struct i2c_client *); 284 285 /* driver model interfaces that don't relate to enumeration */ 286 void (*shutdown)(struct i2c_client *); 287 288 /* Alert callback, for example for the SMBus alert protocol. 289 * The format and meaning of the data value depends on the protocol. 290 * For the SMBus alert protocol, there is a single bit of data passed 291 * as the alert response's low bit ("event flag"). 292 * For the SMBus Host Notify protocol, the data corresponds to the 293 * 16-bit payload data reported by the slave device acting as master. 294 */ 295 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 296 unsigned int data); 297 298 /* a ioctl like command that can be used to perform specific functions 299 * with the device. 300 */ 301 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 302 303 struct device_driver driver; 304 const struct i2c_device_id *id_table; 305 306 /* Device detection callback for automatic device creation */ 307 int (*detect)(struct i2c_client *, struct i2c_board_info *); 308 const unsigned short *address_list; 309 struct list_head clients; 310 311 bool disable_i2c_core_irq_mapping; 312 }; 313 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 314 315 /** 316 * struct i2c_client - represent an I2C slave device 317 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 318 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 319 * @addr: Address used on the I2C bus connected to the parent adapter. 320 * @name: Indicates the type of the device, usually a chip name that's 321 * generic enough to hide second-sourcing and compatible revisions. 322 * @adapter: manages the bus segment hosting this I2C device 323 * @dev: Driver model device node for the slave. 324 * @irq: indicates the IRQ generated by this device (if any) 325 * @detected: member of an i2c_driver.clients list or i2c-core's 326 * userspace_devices list 327 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 328 * calls it to pass on slave events to the slave driver. 329 * 330 * An i2c_client identifies a single device (i.e. chip) connected to an 331 * i2c bus. The behaviour exposed to Linux is defined by the driver 332 * managing the device. 333 */ 334 struct i2c_client { 335 unsigned short flags; /* div., see below */ 336 unsigned short addr; /* chip address - NOTE: 7bit */ 337 /* addresses are stored in the */ 338 /* _LOWER_ 7 bits */ 339 char name[I2C_NAME_SIZE]; 340 struct i2c_adapter *adapter; /* the adapter we sit on */ 341 struct device dev; /* the device structure */ 342 int irq; /* irq issued by device */ 343 struct list_head detected; 344 #if IS_ENABLED(CONFIG_I2C_SLAVE) 345 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 346 #endif 347 }; 348 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 349 350 extern struct i2c_client *i2c_verify_client(struct device *dev); 351 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 352 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 353 const struct i2c_client *client); 354 355 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 356 { 357 struct device * const dev = container_of(kobj, struct device, kobj); 358 return to_i2c_client(dev); 359 } 360 361 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 362 { 363 return dev_get_drvdata(&dev->dev); 364 } 365 366 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 367 { 368 dev_set_drvdata(&dev->dev, data); 369 } 370 371 /* I2C slave support */ 372 373 #if IS_ENABLED(CONFIG_I2C_SLAVE) 374 enum i2c_slave_event { 375 I2C_SLAVE_READ_REQUESTED, 376 I2C_SLAVE_WRITE_REQUESTED, 377 I2C_SLAVE_READ_PROCESSED, 378 I2C_SLAVE_WRITE_RECEIVED, 379 I2C_SLAVE_STOP, 380 }; 381 382 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 383 extern int i2c_slave_unregister(struct i2c_client *client); 384 extern bool i2c_detect_slave_mode(struct device *dev); 385 386 static inline int i2c_slave_event(struct i2c_client *client, 387 enum i2c_slave_event event, u8 *val) 388 { 389 return client->slave_cb(client, event, val); 390 } 391 #else 392 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 393 #endif 394 395 /** 396 * struct i2c_board_info - template for device creation 397 * @type: chip type, to initialize i2c_client.name 398 * @flags: to initialize i2c_client.flags 399 * @addr: stored in i2c_client.addr 400 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 401 * @platform_data: stored in i2c_client.dev.platform_data 402 * @of_node: pointer to OpenFirmware device node 403 * @fwnode: device node supplied by the platform firmware 404 * @properties: additional device properties for the device 405 * @resources: resources associated with the device 406 * @num_resources: number of resources in the @resources array 407 * @irq: stored in i2c_client.irq 408 * 409 * I2C doesn't actually support hardware probing, although controllers and 410 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 411 * a device at a given address. Drivers commonly need more information than 412 * that, such as chip type, configuration, associated IRQ, and so on. 413 * 414 * i2c_board_info is used to build tables of information listing I2C devices 415 * that are present. This information is used to grow the driver model tree. 416 * For mainboards this is done statically using i2c_register_board_info(); 417 * bus numbers identify adapters that aren't yet available. For add-on boards, 418 * i2c_new_device() does this dynamically with the adapter already known. 419 */ 420 struct i2c_board_info { 421 char type[I2C_NAME_SIZE]; 422 unsigned short flags; 423 unsigned short addr; 424 const char *dev_name; 425 void *platform_data; 426 struct device_node *of_node; 427 struct fwnode_handle *fwnode; 428 const struct property_entry *properties; 429 const struct resource *resources; 430 unsigned int num_resources; 431 int irq; 432 }; 433 434 /** 435 * I2C_BOARD_INFO - macro used to list an i2c device and its address 436 * @dev_type: identifies the device type 437 * @dev_addr: the device's address on the bus. 438 * 439 * This macro initializes essential fields of a struct i2c_board_info, 440 * declaring what has been provided on a particular board. Optional 441 * fields (such as associated irq, or device-specific platform_data) 442 * are provided using conventional syntax. 443 */ 444 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 445 .type = dev_type, .addr = (dev_addr) 446 447 448 #if IS_ENABLED(CONFIG_I2C) 449 /* Add-on boards should register/unregister their devices; e.g. a board 450 * with integrated I2C, a config eeprom, sensors, and a codec that's 451 * used in conjunction with the primary hardware. 452 */ 453 extern struct i2c_client * 454 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 455 456 /* If you don't know the exact address of an I2C device, use this variant 457 * instead, which can probe for device presence in a list of possible 458 * addresses. The "probe" callback function is optional. If it is provided, 459 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 460 * a default probing method is used. 461 */ 462 extern struct i2c_client * 463 i2c_new_probed_device(struct i2c_adapter *adap, 464 struct i2c_board_info *info, 465 unsigned short const *addr_list, 466 int (*probe)(struct i2c_adapter *, unsigned short addr)); 467 468 /* Common custom probe functions */ 469 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 470 471 /* For devices that use several addresses, use i2c_new_dummy() to make 472 * client handles for the extra addresses. 473 */ 474 extern struct i2c_client * 475 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 476 477 extern struct i2c_client * 478 i2c_new_secondary_device(struct i2c_client *client, 479 const char *name, 480 u16 default_addr); 481 482 extern void i2c_unregister_device(struct i2c_client *); 483 #endif /* I2C */ 484 485 /* Mainboard arch_initcall() code should register all its I2C devices. 486 * This is done at arch_initcall time, before declaring any i2c adapters. 487 * Modules for add-on boards must use other calls. 488 */ 489 #ifdef CONFIG_I2C_BOARDINFO 490 extern int 491 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 492 unsigned n); 493 #else 494 static inline int 495 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 496 unsigned n) 497 { 498 return 0; 499 } 500 #endif /* I2C_BOARDINFO */ 501 502 /** 503 * struct i2c_algorithm - represent I2C transfer method 504 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 505 * defined by the msgs array, with num messages available to transfer via 506 * the adapter specified by adap. 507 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 508 * is not present, then the bus layer will try and convert the SMBus calls 509 * into I2C transfers instead. 510 * @functionality: Return the flags that this algorithm/adapter pair supports 511 * from the I2C_FUNC_* flags. 512 * @reg_slave: Register given client to I2C slave mode of this adapter 513 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 514 * 515 * The following structs are for those who like to implement new bus drivers: 516 * i2c_algorithm is the interface to a class of hardware solutions which can 517 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 518 * to name two of the most common. 519 * 520 * The return codes from the @master_xfer field should indicate the type of 521 * error code that occurred during the transfer, as documented in the kernel 522 * Documentation file Documentation/i2c/fault-codes. 523 */ 524 struct i2c_algorithm { 525 /* If an adapter algorithm can't do I2C-level access, set master_xfer 526 to NULL. If an adapter algorithm can do SMBus access, set 527 smbus_xfer. If set to NULL, the SMBus protocol is simulated 528 using common I2C messages */ 529 /* master_xfer should return the number of messages successfully 530 processed, or a negative value on error */ 531 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 532 int num); 533 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 534 unsigned short flags, char read_write, 535 u8 command, int size, union i2c_smbus_data *data); 536 537 /* To determine what the adapter supports */ 538 u32 (*functionality) (struct i2c_adapter *); 539 540 #if IS_ENABLED(CONFIG_I2C_SLAVE) 541 int (*reg_slave)(struct i2c_client *client); 542 int (*unreg_slave)(struct i2c_client *client); 543 #endif 544 }; 545 546 /** 547 * struct i2c_lock_operations - represent I2C locking operations 548 * @lock_bus: Get exclusive access to an I2C bus segment 549 * @trylock_bus: Try to get exclusive access to an I2C bus segment 550 * @unlock_bus: Release exclusive access to an I2C bus segment 551 * 552 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 553 */ 554 struct i2c_lock_operations { 555 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 556 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 557 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 558 }; 559 560 /** 561 * struct i2c_timings - I2C timing information 562 * @bus_freq_hz: the bus frequency in Hz 563 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 564 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 565 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 566 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 567 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 568 */ 569 struct i2c_timings { 570 u32 bus_freq_hz; 571 u32 scl_rise_ns; 572 u32 scl_fall_ns; 573 u32 scl_int_delay_ns; 574 u32 sda_fall_ns; 575 u32 sda_hold_ns; 576 }; 577 578 /** 579 * struct i2c_bus_recovery_info - I2C bus recovery information 580 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 581 * i2c_generic_scl_recovery(). 582 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 583 * recovery. Populated internally for generic GPIO recovery. 584 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 585 * Populated internally for generic GPIO recovery. 586 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 587 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 588 * GPIO, for generic GPIO recovery. 589 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 590 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 591 * for generic GPIO recovery. 592 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 593 * has a more complex internal logic than just reading SDA. Optional. 594 * @prepare_recovery: This will be called before starting recovery. Platform may 595 * configure padmux here for SDA/SCL line or something else they want. 596 * @unprepare_recovery: This will be called after completing recovery. Platform 597 * may configure padmux here for SDA/SCL line or something else they want. 598 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 599 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 600 */ 601 struct i2c_bus_recovery_info { 602 int (*recover_bus)(struct i2c_adapter *adap); 603 604 int (*get_scl)(struct i2c_adapter *adap); 605 void (*set_scl)(struct i2c_adapter *adap, int val); 606 int (*get_sda)(struct i2c_adapter *adap); 607 void (*set_sda)(struct i2c_adapter *adap, int val); 608 int (*get_bus_free)(struct i2c_adapter *adap); 609 610 void (*prepare_recovery)(struct i2c_adapter *adap); 611 void (*unprepare_recovery)(struct i2c_adapter *adap); 612 613 /* gpio recovery */ 614 struct gpio_desc *scl_gpiod; 615 struct gpio_desc *sda_gpiod; 616 }; 617 618 int i2c_recover_bus(struct i2c_adapter *adap); 619 620 /* Generic recovery routines */ 621 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 622 623 /** 624 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 625 * @flags: see I2C_AQ_* for possible flags and read below 626 * @max_num_msgs: maximum number of messages per transfer 627 * @max_write_len: maximum length of a write message 628 * @max_read_len: maximum length of a read message 629 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 630 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 631 * 632 * Note about combined messages: Some I2C controllers can only send one message 633 * per transfer, plus something called combined message or write-then-read. 634 * This is (usually) a small write message followed by a read message and 635 * barely enough to access register based devices like EEPROMs. There is a flag 636 * to support this mode. It implies max_num_msg = 2 and does the length checks 637 * with max_comb_*_len because combined message mode usually has its own 638 * limitations. Because of HW implementations, some controllers can actually do 639 * write-then-anything or other variants. To support that, write-then-read has 640 * been broken out into smaller bits like write-first and read-second which can 641 * be combined as needed. 642 */ 643 644 struct i2c_adapter_quirks { 645 u64 flags; 646 int max_num_msgs; 647 u16 max_write_len; 648 u16 max_read_len; 649 u16 max_comb_1st_msg_len; 650 u16 max_comb_2nd_msg_len; 651 }; 652 653 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 654 #define I2C_AQ_COMB BIT(0) 655 /* first combined message must be write */ 656 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 657 /* second combined message must be read */ 658 #define I2C_AQ_COMB_READ_SECOND BIT(2) 659 /* both combined messages must have the same target address */ 660 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 661 /* convenience macro for typical write-then read case */ 662 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 663 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 664 /* clock stretching is not supported */ 665 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 666 /* message cannot have length of 0 */ 667 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 668 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 669 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 670 671 /* 672 * i2c_adapter is the structure used to identify a physical i2c bus along 673 * with the access algorithms necessary to access it. 674 */ 675 struct i2c_adapter { 676 struct module *owner; 677 unsigned int class; /* classes to allow probing for */ 678 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 679 void *algo_data; 680 681 /* data fields that are valid for all devices */ 682 const struct i2c_lock_operations *lock_ops; 683 struct rt_mutex bus_lock; 684 struct rt_mutex mux_lock; 685 686 int timeout; /* in jiffies */ 687 int retries; 688 struct device dev; /* the adapter device */ 689 690 int nr; 691 char name[48]; 692 struct completion dev_released; 693 694 struct mutex userspace_clients_lock; 695 struct list_head userspace_clients; 696 697 struct i2c_bus_recovery_info *bus_recovery_info; 698 const struct i2c_adapter_quirks *quirks; 699 700 struct irq_domain *host_notify_domain; 701 }; 702 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 703 704 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 705 { 706 return dev_get_drvdata(&dev->dev); 707 } 708 709 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 710 { 711 dev_set_drvdata(&dev->dev, data); 712 } 713 714 static inline struct i2c_adapter * 715 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 716 { 717 #if IS_ENABLED(CONFIG_I2C_MUX) 718 struct device *parent = adapter->dev.parent; 719 720 if (parent != NULL && parent->type == &i2c_adapter_type) 721 return to_i2c_adapter(parent); 722 else 723 #endif 724 return NULL; 725 } 726 727 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 728 729 /* Adapter locking functions, exported for shared pin cases */ 730 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 731 #define I2C_LOCK_SEGMENT BIT(1) 732 733 /** 734 * i2c_lock_bus - Get exclusive access to an I2C bus segment 735 * @adapter: Target I2C bus segment 736 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 737 * locks only this branch in the adapter tree 738 */ 739 static inline void 740 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 741 { 742 adapter->lock_ops->lock_bus(adapter, flags); 743 } 744 745 /** 746 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 747 * @adapter: Target I2C bus segment 748 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 749 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 750 * 751 * Return: true if the I2C bus segment is locked, false otherwise 752 */ 753 static inline int 754 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 755 { 756 return adapter->lock_ops->trylock_bus(adapter, flags); 757 } 758 759 /** 760 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 761 * @adapter: Target I2C bus segment 762 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 763 * unlocks only this branch in the adapter tree 764 */ 765 static inline void 766 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 767 { 768 adapter->lock_ops->unlock_bus(adapter, flags); 769 } 770 771 /*flags for the client struct: */ 772 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 773 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 774 /* Must equal I2C_M_TEN below */ 775 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 776 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 777 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 778 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 779 /* Must match I2C_M_STOP|IGNORE_NAK */ 780 781 /* i2c adapter classes (bitmask) */ 782 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 783 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 784 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 785 /* Warn users that the adapter doesn't support classes anymore */ 786 #define I2C_CLASS_DEPRECATED (1<<8) 787 788 /* Internal numbers to terminate lists */ 789 #define I2C_CLIENT_END 0xfffeU 790 791 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 792 #define I2C_ADDRS(addr, addrs...) \ 793 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 794 795 796 /* ----- functions exported by i2c.o */ 797 798 /* administration... 799 */ 800 #if IS_ENABLED(CONFIG_I2C) 801 extern int i2c_add_adapter(struct i2c_adapter *); 802 extern void i2c_del_adapter(struct i2c_adapter *); 803 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 804 805 extern int i2c_register_driver(struct module *, struct i2c_driver *); 806 extern void i2c_del_driver(struct i2c_driver *); 807 808 /* use a define to avoid include chaining to get THIS_MODULE */ 809 #define i2c_add_driver(driver) \ 810 i2c_register_driver(THIS_MODULE, driver) 811 812 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 813 extern void i2c_release_client(struct i2c_client *client); 814 815 /* call the i2c_client->command() of all attached clients with 816 * the given arguments */ 817 extern void i2c_clients_command(struct i2c_adapter *adap, 818 unsigned int cmd, void *arg); 819 820 extern struct i2c_adapter *i2c_get_adapter(int nr); 821 extern void i2c_put_adapter(struct i2c_adapter *adap); 822 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 823 824 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 825 826 /* Return the functionality mask */ 827 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 828 { 829 return adap->algo->functionality(adap); 830 } 831 832 /* Return 1 if adapter supports everything we need, 0 if not. */ 833 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 834 { 835 return (func & i2c_get_functionality(adap)) == func; 836 } 837 838 /** 839 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 840 * @adap: i2c adapter 841 * @quirks: quirk flags 842 * 843 * Return: true if the adapter has all the specified quirk flags, false if not 844 */ 845 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 846 { 847 if (!adap->quirks) 848 return false; 849 return (adap->quirks->flags & quirks) == quirks; 850 } 851 852 /* Return the adapter number for a specific adapter */ 853 static inline int i2c_adapter_id(struct i2c_adapter *adap) 854 { 855 return adap->nr; 856 } 857 858 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 859 { 860 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 861 } 862 863 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 864 void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf); 865 866 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 867 /** 868 * module_i2c_driver() - Helper macro for registering a modular I2C driver 869 * @__i2c_driver: i2c_driver struct 870 * 871 * Helper macro for I2C drivers which do not do anything special in module 872 * init/exit. This eliminates a lot of boilerplate. Each module may only 873 * use this macro once, and calling it replaces module_init() and module_exit() 874 */ 875 #define module_i2c_driver(__i2c_driver) \ 876 module_driver(__i2c_driver, i2c_add_driver, \ 877 i2c_del_driver) 878 879 /** 880 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 881 * @__i2c_driver: i2c_driver struct 882 * 883 * Helper macro for I2C drivers which do not do anything special in their 884 * init. This eliminates a lot of boilerplate. Each driver may only 885 * use this macro once, and calling it replaces device_initcall(). 886 */ 887 #define builtin_i2c_driver(__i2c_driver) \ 888 builtin_driver(__i2c_driver, i2c_add_driver) 889 890 #endif /* I2C */ 891 892 #if IS_ENABLED(CONFIG_OF) 893 /* must call put_device() when done with returned i2c_client device */ 894 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 895 896 /* must call put_device() when done with returned i2c_adapter device */ 897 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 898 899 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 900 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 901 902 extern const struct of_device_id 903 *i2c_of_match_device(const struct of_device_id *matches, 904 struct i2c_client *client); 905 906 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 907 struct i2c_board_info *info); 908 909 #else 910 911 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 912 { 913 return NULL; 914 } 915 916 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 917 { 918 return NULL; 919 } 920 921 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 922 { 923 return NULL; 924 } 925 926 static inline const struct of_device_id 927 *i2c_of_match_device(const struct of_device_id *matches, 928 struct i2c_client *client) 929 { 930 return NULL; 931 } 932 933 static inline int of_i2c_get_board_info(struct device *dev, 934 struct device_node *node, 935 struct i2c_board_info *info) 936 { 937 return -ENOTSUPP; 938 } 939 940 #endif /* CONFIG_OF */ 941 942 #if IS_ENABLED(CONFIG_ACPI) 943 u32 i2c_acpi_find_bus_speed(struct device *dev); 944 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 945 struct i2c_board_info *info); 946 #else 947 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 948 { 949 return 0; 950 } 951 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 952 int index, struct i2c_board_info *info) 953 { 954 return NULL; 955 } 956 #endif /* CONFIG_ACPI */ 957 958 #endif /* _LINUX_I2C_H */ 959